Lure by Brian Rathbone (Sam Flock Adventures: Book One)

Warning: This book contains sexual content, bad behavior, and mild profanity. Sam Flock is a good cop, but when she has a paranormal experience on the job that causes her to drive into the side of an ambulance, her career in law enforcement meets its end. Determined to find answers, she forms a paranormal investigation agency with her friend, Shells. Though they are perhaps the world's worst paranormal investigators, they find something beyond their wildest imaginings.